Showy rattlebox (
Crotalaria spectabilis) is an erect, summer annual that is found worldwide, including throughout the South eastern United States.
Showy Rattlebox Toxic Components
Crotalaria species contain pyrrolizidine alkaloids (PAs) that can cause
pyrrolizidine alkaloid toxicity which can result in liver failure. Liver enzymes convert the alkaloids into toxic pyrroles that poison liver and lung cells. In South Africa, they have been shown to cause respiratory disease in horses, referred to as "jaagsiekte" poisoning.
Cases of Showy Rattlebox Poisoning
The most common cause of poisoning cases has been through unknowingly feeding horses contaminated hay and feed. Horses need only to consume 1.5 to 3% of their body weight of the plant parts to start to show symptoms of toxicity. Crotalaria poisoning may be acute or chronic. The chronic form of poisoning is most common, and may take several months to years accumulate to where the horse demonstrates symptoms. The acute form appears within a few days after a substantial amount of showy rattlebox is consumed.
What Showy Rattlebox Looks Like
- Early growth: Turns maroon with age; covered with short hairs. First leaves are alternate, without hairs on the upper portion of the leave, however is covered with appressed hairs along the lower surface of leaves.
- Root: Taproot
- Stem: Green to purplish, erect (up to 6 ½ ft in height), stout; become waxy and angled slightly as they age.
- Leaves: Alternate, 2-6 inches in length; wide at the apex and tapers to the base. Hairless on the upper surface and covered with appressed hairs on the lower surface; occur on short petioles.
- Flowers: Large, bright yellow, showy flowers that are on elongated inflorescences and stalked from a central axis.
- Fruit: 1-2 inch long legume that turn brown to black as they mature. Seeds contained within fruits often cause a “rattlebox” sound when shaken.
